You can set the ContourLevels property of the ContourSeries.
Currently, it is not possible to fill the gap between the contour levels.
But you can add a HeatMapSeries before the ContourSeries - see the examples.
If you use a RangeColorAxis, I think you can get almost the same result.

Thank you for your answer. Unfortunately, it did not solve my problem.
Actually, I code in VB.net, not in C#.
I'm trying to translate the example code from C# to VB.net, but I have errors.
Particularly, I don't know how to translate this line :